My Boyfriend Tells Me That He Notices A Connection That

My boyfriend tells me that he notices a connection that everytime he eats my vagina, that the corners of his mouth turn cracked, almost like he has a scab that hurts when he opens his mouth. Please help me, I only have sex with him and that's going on for over a year and a half. I got tested for everything last October and I was clean? He says that he's made the correlation in the last six month but it may have been going on for about 10. Thanks